NO. 4 



SUN S VARIATION AND TEMPERATURES — ABBOT 



13 



pared, I found that the temperature effects usually occurred in these 

 western cities some days earlier than at Washington, as was expected. 

 These delays average nearly in accord with the findings of H. H. 

 Clayton * from a study of the progress of a 7-day wave of atmospheric 

 disturbance from Alaska to the Atlantic coast. Figure 6 gives the 

 mean temperature effects for January and October at Helena and St. 

 Louis for the years 1924 to 1943. 



Fig. 6. — Graphs derived as in table 4 and figure 4, for mean effects of the 

 6.6456-day period on St. Louis and Helena temperature departures for months 

 of January and October of all years from the year 1924 to 1943. Ordinates are 

 degrees Fahrenheit. 



7. THE 6.64S6-DAY PERIOD IN THE SOLAR EMISSION 



Leaving temperature records for the moment, I pass now to the 

 determination of the actual changes in the emission of radiation of the 

 sun itself, which accompany these large periodic changes in the tem- 

 perature at Washington and elsewhere. I shall employ extensively the 

 solar-constant measures of Montezuma, Chile, 1924 to 1944, to de- 

 termine these solar changes. 



Between January 1924 and December 1944 there were about 1,150 

 recurrences of the period of 6.6456 days. There dates have all been 



* Smithsonian Misc. Coll., vol. 82, No. 7, fig. 14, p. 22, 1930. 



